Spray protection ring

ABSTRACT

The invention relates to a spray protection ring for pipe flanges consisting of a clamping wall, which covers the flange crack when placed on the peripheral surfaces of the flange. An annular connector (9) protrudes radially inwards from the clamping band. A radial and axial element (11) is joined to this connector, and serves as a spacer for an annular screen-like element (12) which extends around the periphery and acts as a valve. The connector (9) and the connected element (11) have a plurality of slits (50) distributed around the periphery. These slits (50) are out-of-line in peripheral direction in relation to a plurality of slits (40) distributed around the periphery of the screen (12). Before mounting, the axial extension of the screen (12) is slightly greater than the distance between the facing flange surfaces (20, 21).

The invention relates to a spray protection ring for pipe flangesconsisting of a clamping wall covering a flange gap when placed on thecircumferential surfaces of a flange, with a ring-shaped umbrella-likeslotted shielding element extending radially, the axial extent of theshielding element in the radial direction before being installed beingslightly larger than the distance between the surfaces of the flangesfacing each other.

Spray protection rings mounted on pipe flanges serve to protect theenvironment when leakage occurs in a flange connection. Personnel in thevicinity are to be shielded from liquid escaping under pressure, and itis to be noted in this context that flange connections with no sprayprotection ring may allow a positively life-threatening stream of liquidto escape if a leak occurs.

State-of-the-art spray protection rings (29 32 259 C2 and DE-U 70 37277.9) are unable to provide the safety desired. This is to be ascribedmostly to the fact that it is not possible to remove sufficient energyfrom liquid emerging under pressure.

This invention remedies this defect; it has the object of ensuringescape of liquid from pipeline connections under pressure withoutspraying in the event of seal malfunction.

This is accomplished in that a ring-shaped connector projecting radiallyinward from the clamping band, together with an element extendingradially-axially integral with it acting as a spacer, is provided forthe ring-shaped shielding element extending peripherally and acting as avalve, and in that the connector and the element integral with it have aplurality of slots distributed over the circumference which are offsetcircumferentially from a plurality of slots in the shield.

A spray protection ring for pipe flanges of the kind indicated above isdisclosed in DE-PS 31 46 803 and EP 00 80 654 A1). In the case of thisclamping band, which is positioned over the two flange leaves and theenclosed gap, between the flanges there is an annular deflection spacewith a deflecting surface for escaping liquid. There is also provided adownstream cushion space into which a liquid flows and in which itspressure is reduced. The two spaces communicate with each other throughapertures in the partitions. This results in the formation of partialliquid streams flowing in opposite directions, so that the liquidgradually transfers its kinetic energy through deflection, impact, andpressure reduction into a zero-pressure space.

The present invention does not have the object of generating partialliquid streams, nor that of reducing kinetic energy by pressurereduction. In the spray protection ring claimed for the invention thereis provided on the interior surface of the clamp band as spacer aring-shaped connector projecting radially inward; this effectstransition to a ring-shaped shield element acting as a valve, in such away that it presents the appearance of a question mark when viewed inaxial cross-section. In order for it now to be possible for a structuresuch as this to be moved over the flange and clamped together on thediameter of the flange, a plurality of slots, which nevertheless are forall practical purposes closed when the spray protection ring is in theoperating position, are distributed over the circumference in thering-shaped connector.

Liquid escaping as a result of leakage between pipe flanges strikes theprotection ring opposite it, and only a very small part of it manages tomove through the slots distributed over the circumference to enter thespace beyond them and immediately reach the clamping band without theoccurrence or involvement as a factor of any form of deflection or evenrebound processes. Part of this flow may be propagatedcircumferentially, since the slots in the protection ring are offsetcircumferentially from those in the connector.

In the event of leakage in the flange connection first the space fillswith liquid radially inside the protection ring, since the two axialperipheral surfaces of the protection ring rest more or less immobile onthe surfaces of the flanges. If the pressure of the liquid issufficiently high, the protection ring rises from the flange surface orsurfaces so that sufficient energy is removed from the liquid as aresult of the process and through the subsequent eddy processes.

These eddy processes and the valve action of the protection ring areessential to the efficiency of this invention. Deflection processes,division into partial streams, rebound relationships, and pressurereduction processes are not provided.

The invention is described in what follows on the basis of an exemplaryembodiment, with reference to the drawing, in which

FIG. 1 presents a side view of a spray protection ring as claimed forthe invention,

FIG. 2 a detailed view along A--A in FIG. 1, on an enlarged scale.

FIG. 1 shows a top view of a spray protection ring as installed, and inthe upper area parts serving to draw the spray protection ring togetherafter it has been positioned over the flange and in the process also togenerate a permanent force acting in the circumferential direction.

By means of the permanent force, the upper area parts maintain the sprayprotection ring in a suitable circumferential size.

FIG. 2 presents a cross-sectional view, and shows in particular aclamping band 10 which is positioned over the exterior surfaces of twoadjacent flanges 20 and 21.

A ring-shaped connector 9 projects inward from the circumference of theclamping band 10 and continues radially inward in the form of anaxially-radially oriented extension element 11. The two elements 9 and11 have openings in the form of a plurality of slots 50 distributed overthe circumference, so that a relatively large ring-shaped sprayprotection ring may be positioned over a smaller flange connection andtightened over this connection. Element 11 effects transition to becomean umbrella-shaped element 12 which extends between the oppositesurfaces of flanges 20 and 21 and is more or less restrained or jammedbetween these surfaces. The umbrella-like element 12 shields the spacefurther inward between the two flanges 20, 21 from the exterior. Liquidimpinging on the shield in the area of 13 is initially repelled by thelatter and ultimately reaches the space situated radially outside theshield 12, by way of the opening shield 12, which acts as a valve. Theliquid present has expended its energy as a result of the process ofopening the shield or valve element 12 and subsequent eddy processes tothe extent that no hazardous stream of liquid can escape from the flangeconnection.

The shield element 12 as well has slots 40 in it distributed over thecircumference, to make it at all possible for the spray protection ringas already described to be drawn together.

FIG. 1 shows that the two slot arrangements are offset from each otherso that liquid which might escape between the slots 40 can reach theslots 50 only when flowing circumferentially.

What is claimed is:
 1. A spray protection ring for pipe flanges thathave an axial space therebetween, comprising:an annular clamping band; aring-shaped connector (9) including a spacer extending radially inwardfrom the clamping band and a shield (12) positioned radially inward ofthe spacer, each of said spacer and said shield defining acircumference; and parts maintaining the spray protection ring in asuitable circumferential size, wherein the spacer has a plurality ofspacer slots distributed over the circumference of the spacer, and theshield has a plurality of shield slots distributed over thecircumference of the shield, wherein the shield slots are offset in thecircumferential direction from the spacer slots.
 2. The spray protectionring of claim 1, wherein the shield has an axial dimension sufficientfor the shield to span the space between the flanges.
 3. The sprayprotection ring of claim 2, wherein the shield has a first side adaptedto engage one of the flanges and a second side adapted to engage theother of the flanges, the shield curving radially inward between thefirst and second sides.